1. Field of the Invention
The present invention relates to a crossed roller bearing in which cylindrical rollers are inserted into an annular race of rectangular cross-section so as to be in an alternatingly crossed state. More specifically, the present invention relates to an improvement to a crossed roller bearing retainer in which the rollers are held at a fixed spacing so that adjacent rollers are not in contact.
2. Description of the Related Art
With crossed roller bearings, a spacer retainer is disposed between rollers that are inserted into a race having a rectangular cross-section, thereby holding the rollers at a fixed spacing so that they do not touch. The spacer retainer is provided with a concave surface that is in surface contact with the circular outer circumferential surfaces of the adjacent rollers as disclosed in FIGS. 2 and 5 of Patent Document 1, in FIG. 4 of Patent Document 2, and in Patent Document 3 below.    [Patent Document 1] JP-A 10-141363    [Patent Document 2] JP-A 05-276768    [Patent Document 3] JP-B 3424875
The spacer retainers proposed in the Patent Documents above have complex shapes with surfaces that follow a concave surface, allowing surface contact with the circular external circumferential surfaces of the rollers. There are thus problems with non-trivial production as well as comparatively high production costs that remain to be resolved. Moreover, as disclosed in Patent Document 3, skill is required in designing the shape so that grease is adequately supplied to each section of the race.